1. Field of the Invention
The present invention relates to a piezoelectric vibrating piece, a piezoelectric vibrator, an oscillator, an electronic apparatus and a radio controlled timepiece.
2. Background Art
A piezoelectric vibrator is used in various devices as a time source, a timing source of a control signal, a reference signal source or the like. The piezoelectric vibrator has a structure in which a piezoelectric vibrating piece is accommodated in a package.
For example, as disclosed in JP-A-2006-345519, the piezoelectric vibrating piece includes a pair of vibrating arm sections, a base section provided between the pair of vibrating arm sections, and a connecting section connecting each of the pair of vibrating arm sections and the base section. If a voltage is applied to excitation electrodes formed in the vibrating arm sections, in the piezoelectric vibrating piece, the vibrating arm sections conduct bending vibration at a predetermined frequency.
In such a piezoelectric vibrating piece, power that is required for vibration is reduced in proportion as Crystal Impedance (CI) value of the piezoelectric vibrating piece is small, and it is possible to reduce the power consumption of various devices using the piezoelectric vibrating piece.
If the piezoelectric vibrating piece is expressed as an equivalent circuit, the CI value of the piezoelectric vibrating piece is often expressed as a series resistance value (hereinafter, simply referred to as a resistance value) and is also expressed as the resistance value in the specification. In the piezoelectric vibrating piece that is provided in the present situation, the resistance value is approximately 50Ω to 80Ω, for example, if an output frequency thereof is 32.768 kHz.